Just listened to a Lead Free presentation by one of our assembly materials suppliers. They tested different pastes on different board finishes using a variety of different patterns, spacings, aperture sizes, etc,... By far and away, ENIG was the best finish for performance, for wetting, defects, voiding, ... The guy making the presentation said that he felt a lot of the initial concerns re ENIG - black pad being the biggest - have been resolved, and that they are no longer a concern, that they have determined what the cause of it is and eliminated it. Anyone want to comment on that? I'm not sure if he is correct, or just out of the loop. It was interesting as well: ImmAg got a very bad rating from them in performance, even though many on this forum really praise that finish. It exhibited dewetting (they printed solderpaste pads on an area with no soldermask, and the solder did not stay and spread where it was printed, it crept together with other pads into a big blob, like you might see a water drop do) and the amount of voiding was impressive!! About 4 years ago I joined this forum, and one of the reasons was because I was looking for info on ENIG. We had done a prototype run of a couple of boards and they failed miserably. They were never analyzed in depth, so it wasn't figured out what exactly caused the failure. It was the excuse we needed to not choose this finish and some of the extra costs associated with it. However, with the Pbfree push now, I don't know if we should re-examine whether to use the finish. For products where we needed a flat finish, we have gone to ImmSn, but we still use HASL wherever possible. Genny "Genius may have its limitations, but stupidity is not thus handicapped" Elbert Hubbard --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------